This invention relates to an aqueous emulsion comprising ethylene-vinyl ester copolymer and a polyoxyalkylene nonionic surface active agent.
Aqueous emulsions comprising an ethylene-vinyl ester copolymer such as ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-vinyl chloride copolymer and ethylene-vinyl acetate-alkyl acrylate copolymer have been widely used, for example, for an adhesive, a coating agent, a paint, a binder for paper, fiber, wall paper and an admixture of cement.
As these aqueous emulsions, those comprising polyoxyalkylene phenyl ethers such as polyoxyethylene nonylphenyl ether as a nonionic surface active agent are excellent in storage and mechanical stabilities and have excellent strength after use, that is, in the dried state. (JP-A-06-065550, JP-A-06-009934, JP-A-11-071434, etc) Therefore, they are used favorably used.
However, the conventional aqueous emulsions are insufficient in water resistance in the dried state, and further improvement in the water resistance has been required. The object of the present invention is to provide an aqueous emulsion comprising ethylene-vinyl ester copolymer which gives an improved water resistance in the dried state.
Under such situation, the inventors of the present invention have conducted extensive investigations and have found that above problems can be solved by using an aqueous emulsion comprising ethylene-vinyl ester copolymer, as the polyoxyalkylene nonionic surface active agent, which comprises polyoxyalkylene alkyl ethers at a specific amount and substantially no polyoxyalkylene phenyl ethers Thus, they have completed the present invention.